Referring to FIGS. 1A and 1B, a prior art curtain is illustrated. The curtain has an upper beam 1, a curtain body 2 and a control rope set 3. The upper beam has a front receiving chamber 4 and a rear receiving chamber 5. The front receiving chamber 4 can be embedded by the curtain body 2 so as to be connected to the upper beam. Another end of the curtain body 2 suspends downward. The rear receiving chamber 5 is arranged with an auto slide-stop 6 and a pulley 7. One end of the control rope set 3 is a rope 8, and another end is a rope 9. The rope 8 stops at a predetermined position by the auto slide-stop 7. The rope 9 winds around the curtain body 2. A distal end A of the rope 9 is embedded into the front receiving chamber 4 so that the rope 9 is combined to the upper beam. By pulling the rope 8, the curtain 2 can be wound upwards.
When the rope 9 winds around the curtain 2, the rope 9 will form a circle. Generally, children can not know the danger of the circle. Once the circle encloses the neck of the child, and the rope 8 is pulled, the rope 9 will move upwards. As a result, an accident occurs. This is because no safety structure exists between the rope 9 and the upper beam. Thereby, this prior art is dangerous at home and necessary to be improved.